A dour first half with little scoring opportunities left it 3-0 at halftime in Temple Hill before a lively second half performance produced tries from Corey Hircock and CJ Stander.
In a stop start affair the first half relied on defensive efforts from both sides as Plymouth excelled in the scrum denying Munster any attacking position from the set-piece, while Munster held their own in the lineout and maul.
Scott Deasy missed an opening penalty chance after 3 minutes and Plymouth's Ruairi Cushion followed suit 13 minutes later when he was unlucky to have his kick come back off the upright.
Cushion missed his second chance on the half hour mark before Deasy put the first points on the board in the 40th minute when he struck a great 47 metre kick to give Munster the 3 point margin.
The points came at a pivotal time for Munster as the scrum became the focal point and they were forced to close out the first half with only 13 men after James Cronin was binned for collapsing the scrum and a minute later Sean Dougall was carded for playing the scrumhalf at the ruck.
The pack addressed their issues at the break and the second half saw an improvement in the Munster scrum and the side were able to build a number of attacking phases from it.
CJ Stander led the pack as he broke through the Plymouth defence carrrying the ball into the 22. In the next play Deasy opted for the cross field kick and found replacement Corey Hircock to cross over the line in the corner.
The forwards continued their dominance and were rewarded for their much improved scrummaging when Plymouth prop Jack Andrew was penalised for his bind and sent to the bin in the 59th minute. With the scrum re-set in front of the posts and the numbers advantage, CJ went himself and touched down for Munster's second try. Deasy added the conversion.
Talking to Ian Costello following the win he said "The first 8 to 10 minutes were key for me, it showed our intent, but to come away without a score from that phase of play showed we certainly had a battle on our hands and that we also had to get to grips with our scrums."
"When we were reduced to 13 men I think the boys showed great character and determination to stand up and have a strong finish to that half. We chatted at halftime and they addressed it, and we kicked on from there with the possession."
"In the end we were unlucky not to score more but the focus of the night was to get the four points to qualify."
"It was great we got to use all our bench as well, Academy players Darren Sweetnam and Brian Haugh both made their A debuts, Darren replaced Danny Barnes who had earlier taken a knock to the ribs."
"We know we have secured a quarter final place and that we're going to have to travel but with the postponed games in the UK we'll have to wait and see who we get next."
Munster A: J Murphy; R O Mahony, D Barnes (D Sweetnam 61), I Dineen, L O Dea (C Hircock 40); S Deasy, C Sheridan (B Haugh 75); J Cronin, D Casey (N Scannell 60), C Condon (A Cotter 52); D Foley (B Hayes 69), I Nagle; Dave O'Callaghan, S Dougall capt., (R Murphy 72), CJ Stander Replacements: A Cotter, N Scannell, B Hayes, R Murphy, B Haugh, C Hircock, D Sweetnam.
Plymouth Albion: R McAtee, L Warner, K Fisilau, B Armitage, T Bowen, R Cushion, P Rowley (P Bailey 73), J Andrew (B Rogers 59), L Cowan-Dickie (J Salter 71), A Brown (L Fairbrother 71), H Tovey (H Stupple 72), W Carrick-Smith, R Nasiga, S Hocking, A Carpenter capt. (S Matavesi 56 A Brown 81) Replacements: T Howley-Berridge, P Bailey, B Rogers, L Fairbrother, J Salter, H Stupple, S Matavesi.
